Week 1 Day 3 & Wk 2 Day 4Neuron Basics, Resting Neurons, Graded Potentials, Action potentials

Question 1

Neuron

Answer 1

A single unit

Question 2

Nerve fiber

Answer 2

Axon from a single neuron

Question 3

Nerve

Answer 3

A collection of axons outside of the brain/spinal cord

Question 4

Glial cells

Answer 4

Non neuronal support cells

Question 5

Where is the action potential traveling on a neuron cell?

Answer 5

The action potential is traveling down the axon which transmits electrical signals

Question 6

What is included on CNS?

Answer 6

The Brain and spinal cord

Question 7

What’s another name for glial cells

Answer 7

Myelin

Question 8

What are the two types of Myelin, what do they do, and which nervous system are they part of

Answer 8

Schwann cells: wraps around one axon (PNS)

Oligodendrocytes: covers many axons (CNS)

Question 9

How do electrical and chemical signals work as it pertains to neurons?

Answer 9

Neurons send electrical signals within the cell and chemical signals between cells.

Question 10

In terms of physics, how do you generate electrical potential?

Answer 10

By physically separating + and - charges generates electricity

Question 11

What is the distribution of positive and negative charges for a cell?

Answer 11

The inside of a cell is always more negative than the outside

Question 12

What voltage is a non-excitable cell?

Answer 12

-5mv

Question 13

What voltage is a excitable cell? What voltage is the resting membrane potential?

Answer 13

• 70mV

- 70mv

Question 14

What is the definition of disequilibrium as it pertains to charge?

Answer 14

When the charge is away from 0

Question 15

What is the definition of equilibrium as it pertains to charge?

Answer 15

When the charge is 0 or moving closer to 0

Question 16

What is the definition of polraized as it pertains to charge?

Answer 16

Separation of + & - charge

Question 17

What is the definition of depolarized as it pertains to charge?

Answer 17

Removing polarization (bringing + & - charge together) and moving towards equilibrium. The charge is becoming more positive

Question 18

What is the definition of hyperolarized as it pertains to charge?

Answer 18

Making it more polarized, therefore more negative.

Question 19

Are leak channels always closed or open?

Answer 19

Leak channels are always open

Question 20

Where is a majority to the Na in relation to inside the cell or outside the cell?

Answer 20

A majority of the NA is outside the cell

Question 21

Where is a majority to the K (potassium) in relation to inside the cell or outside the cell?

Answer 21

There’s more K inside the cell

Question 22

For the neuron cell, where do the Na+ concentration and electrical gradients move?

Answer 22

Both the concentration and electrical gradients move inside.

Question 23

For the neuron cell, where do the K+ concentration and electrical gradients move?

Answer 23

The K concentration moves outside and the electrical gradient (+) moves inside

Question 24

When is an ion at equilibrium potential (E)?

Answer 24

when the electrical gradient is equal to and opposite the chemical gardient

Question 25

Because the equilibrium potential for Potassium (-90mV) and sodium (60mV) are different, a neuron cannot exist at both potentials. What does this indicate about at least one ion?

Answer 25

This indicates that one ion will always be in a one direction net flux.

Question 26

What is the definition of Graded potential?

Answer 26

Small, local changes in membrane potential in the dendrites and/or cell body

Question 27

When a neurotransmitter binds to a receptor of a neuron cell, what happens to the Excitatory postsynaptic potential?

Answer 27

The membrane of the neuron cell becomes more positive (depolarized)

Question 28

When a neurotransmitter binds to a receptor of a neuron cell, what happens to the inhibitory postsynpatic potential (IPSP)?

Answer 28

The membrane becomes more negative (more polarized/hyperpolarized) because the positive charges go to it

Question 29

On a neuron cell, what effect does distance have on the Graded potential?

Answer 29

The GP would decrease with increase distance

Question 30

Can GPs leak? If so, what properties is it reliant on. GPS and combine to create a stronger_____

Answer 30

Strength/size of stimulus, distance, and time | Strength/size of stimulus

Question 31

How do you trigger a Graded potential (GP)

Answer 31

NT binds to receptor —>opens ligated channel —> + or - ions flow in/out —->GP

Question 32

When does a action potential (AP) start?

Answer 32

When the GP cross the threshold

Question 33

What is the peak of Action potentials?

Answer 33

+30mV

Question 34

Na+ will flow into the cell until what value?

Answer 34

+60mV?

Question 35

K+ will flow out of the channel until what value?

Answer 35

-90mV

Question 36

What are the 3 types of voltage-gated Na channels states?

Answer 36

closed, open, inactivated

Question 37

For voltage gated Na+ channels, when does the inactivated gate occur?

Answer 37

Shortly after threshold is met and it depolarizes

Question 38

When does a voltage gated K channel open?

Answer 38

When the threshold is met/during depolorization events

Question 39

When a cell is at -70mV, are the voltage gated Na & K channels open or closed?

Answer 39

Closed

Question 40

What voltage is threshold potential?

Answer 40

-55mV

Question 41

What are the three properties of AP? Define each

Answer 41

Threshold, all or none, refractory period Threshold: minimum required depolarization to initiate All or none: The AP either fires or doesn’t Refractor period: once a change in mb has been fired, there is period before anther change can happen

Question 42

What voltage do the Ligan gated channel bring the mb potential to?

Answer 42

-55mV which is threshold

Question 43

What is the clinical significance of local anesthetics on our neurons?

Answer 43

These anesthetics (Lidocaine and novocaine) work by blocking VG Na+ channels

Question 44

What are the two types of refractory period?

Answer 44

Absolute & relative refractory period

Question 45

Define absolute refractory period

Answer 45

When all of VG Na+ channels are either open or inactivated

Question 46

Define the relative refractory period?

Answer 46

When VG Na+ channels are closed or inactive

Question 47

What is the function of the node of ranvier spaces?

Answer 47

The spaces between schwann cells where pumps and VG channels still exist

Question 48

Define convergence as it pertains to neurons

Answer 48

When a bunch of presynaptic neurons affect a single postsynaptic neuron

Question 49

In a neuron, what produces NT

Answer 49

Ribosomes

Question 50

Define what happens during Anterograde.

Answer 50

NT is produced in the cell body and sent down the axon

Question 51

Define what happens during retrograde

Answer 51

When NT are recycled and brought back to the neuron

Question 52

Where is a majority of the Calcium; Inside or outside the neuron. Based on that, how does the concentration gradient of calcium move?

Answer 52

- More Ca 2+ is outside | - Ca 2+ will flow into the VG Ca 2+ channels

Question 53

What causes the VG Ca 2+ channels to open?

Answer 53

A wave of depolarization from Na and K

Question 54

What are the 3 ways of stopping the NT signal>?

Answer 54

Reuptake (recycled) Diffusion Breakdown

Question 55

What do Neuromodulators (NM) do?

Answer 55

-they affect post-synaptic cell’s response to NT

Question 56

What are the two types of Acetylcholine (ACh) (NT) receptors?

Answer 56

-nACHR (located at neuromuscular junction) and mAChr (located at cardiac muscle)

Question 57

What breaks down Acetylcholine in the synapse?

Answer 57

Acetylcholinesterase breaks it down in the synapse

Question 58

What type of receptor is on skeletal muscle?

Answer 58

-nAChR receptor

Question 59

How does nicotine relate to Acetlycholine?

Answer 59

Smoking nicotine can cause Acetylcholine to be released which binds to the nACHr receptor

Question 60

How does Botox and Acetylcholine work together?

Answer 60

Botox prevents acetylcholine from being released which therefore prevents skeletal muscles from contracting (so you still look young!!!)

Question 61

How does Alzheimer’s affect Acetylcholine?

Answer 61

Alzheimer’s specifically targets Acetylcholine neurons.

Question 62

How could amyloid beta negatively affect neurons?

Answer 62

Amybloid beta stick to teach other and tangles in the synapse of neurons, preventing signals from passing through

Question 63

What are the 6 neurotransmitter or Neuromodulators that we must know for the semester?

Answer 63

Acetylcholine, norepinephrine, epinephrine, endogenous, opioids, and oxytocin

Question 64

What are Biogenic amines? What do they do?

Answer 64

- Small and charged molecules derived from molecules | - they help create norepinephrine

Question 65

What does Norepinephrine do?

Answer 65

Norepinephrine is used throughout the NS to mobilize brain and body for action (fight or flight)